Medical facilities, licensed pharmacist or physicians may produce individual pharmaceutical compositions by blending together various ingredients, such as one or more active pharmaceutical ingredient (API) and pharmaceutically acceptable excipients, diluent or solvents, to create a medicine product tailored to the needs of an individual patient. Such activities are commonly referred as pharmaceutical compounding. Practically speaking, in the context of pharmacy compounding, the pharmacist will typically prepare such product tailored to the needs of an individual patient based on a medical prescription.
Pharmaceutical compounding involves blending of the composition ingredients, which is typically performed using manual mixing, for example, using a pestle and mortar. However, manually mixing ingredients can be time-consuming and is often prone to cross-contamination from poorly decontaminated or sterilized equipment used for the mixing. Along with the contamination risk, there is also the problem that performing manual mixing often results in products that face repeatability and/or quality challenges. In other words, it is often difficult to obtain compositions having consistent concentrations of API from one composition to another and/or consistent homogeneous API concentration within one preparation per se. This may result in substantial qualitative differences during manufacture of the same recipe, which at minimum can have an effect on the effectiveness of the recipe.
In this regard, various practical devices have been previously suggested to overcome the above deficiencies of compounding pharmaceutical compositions using manual mixing.
U.S. 2012/0269029 (Konietzko) describes a program-controlled mixer, which includes a control unit, a motor-driven mixing unit with a blade mixing tool, which engages into a mixing vessel, and a lift unit. The lift unit produces an axial relative motion between the blade mixing tool and the mixing vessel, to move the blade mixing tool in the mixing vessel between an upper end position and a lower one, preferably at a constant lifting speed.
A deficiency associated with many mixing devices is that they often involve mixing using blades that contact the mixture causing high shearing forces, which can generate so much heat during mixing so as to degrade thermally labile API.
Additionally or alternatively, many mixing devices often entrain air into the composition being mixed. The entrained air forms air bubbles in the composition modifying thereafter the specific gravity of the pharmaceutical composition. Since the specific gravity is the ratio of the density of the composition to the density of a reference substance; equivalently, it is the ratio of the mass of the composition to the mass of a reference substance for the same given volume. Variations in specific gravity of a composition can be detrimental in that such variations alters the aforementioned ratio and, accordingly, alters the API weight content which is filled in a pharmaceutical container for a given volume of composition filled in. This is particularly critical for pharmaceutical dispensing devices dispensing measured doses which need to dispense consistent amounts of API for a given volume from one device to another one, and from one dispensed volume to the next in the same dispensing device.
In other cases, the entrained air must be removed in order to eliminate the air bubbles from the pharmaceutical composition and thereby improve the appearance of the pharmaceutical composition. For instance, in the production of either translucent or transparent pharmaceutical compositions, it is mandatory to remove the air bubbles since these would otherwise negatively affect the translucency or transparency of the pharmaceutical compositions by imparting opacity zones thereto. However, such de-aeration is time consuming, lowers throughput and generally requires additional vacuum configurations, which can be cumbersome and increase overall manufacturing costs.
Additionally or alternatively, many mixing devices often require mixing in device-specific mixing containers, which thus requires an additional step of decanting the pharmaceutical mixture into a dispensing device container, thereby increasing the risk of material loss during the decanting procedure. Device-specific containers also limit the volume and/or mass of materials that can be mixed to die specifications of such containers, which is not always ideal from a practical perspective. Device-specific containers also require implementing strict cleaning/sterilization procedures to avoid cross-contamination risk when one wishes to reuse the same mixing containers, which can be cumbersome and time-consuming. Otherwise, operation costs and waste are increased when container are used and are discarded after each mixing procedure, i.e., when used as single-use mixing containers.